Dear Developers, since Target Display Mode was introduced you could connect a MacBook to an iMac and use it as second display. You could also switch the sound to the iMac which is great, because it has better Sound. The feature to make the sound come out of the iMac in Target Display mode is broken since Mojave. It‘s also been reported in forums and via bug reports with no response from the Developers. https://discussions.apple.com/thread/8589374 Will this be fixed in Catalina? Best S.